U.S. patent number 7,862,158 [Application Number 11/840,404] was granted by the patent office on 2011-01-04 for method of manufacturing ink jet recording head, ink jet cartridge.
This patent grant is currently assigned to Canon Kabushiki Kaisha. Invention is credited to Kenji Fujii, Shuji Koyama, Hiroyuki Murayama, Shingo Nagata, Masaki Osumi, Yoshinori Tagawa, Yoshinobu Urayama, Jun Yamamuro.
United States Patent |
7,862,158 |
Fujii , et al. |
January 4, 2011 |
Method of manufacturing ink jet recording head, ink jet
cartridge
Abstract
A method of manufacturing an ink jet head which discharges ink,
comprising: a step of preparing a silicon substrate; a step of
forming a membrane having a layer in which a plurality of holes are
disposed to constitute a filter mask, and a layer with which a
first surface is coated in such a manner that the first surface is
not exposed from the plurality of holes on the first surface of the
substrate; a step of forming a close contact enhancing layer on the
membrane formed on the substrate; a step of forming a channel
constituting member on the close contact enhancing layer to
constitute a plurality of discharge ports and a plurality of ink
channels communicating with the plurality of discharge ports; a
step of forming an ink supply port communicating with the plurality
of ink channels in the silicon substrate by anisotropic etching
from a second surface facing the first surface of the substrate;
and a step of forming a filter in a portion of the close contact
enhancing layer positioned in an opening of the ink supply port
using the layer of the membrane in which a plurality of holes are
disposed as the mask.
Inventors: |
Fujii; Kenji (Kanagawa,
JP), Koyama; Shuji (Kanagawa, JP), Osumi;
Masaki (Kanagawa, JP), Nagata; Shingo (Tokyo,
JP), Yamamuro; Jun (Kanagawa, JP), Tagawa;
Yoshinori (Kanagawa, JP), Murayama; Hiroyuki
(Kanagawa, JP), Urayama; Yoshinobu (Kanagawa,
JP) |
Assignee: |
Canon Kabushiki Kaisha (Tokyo,
JP)
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Family
ID: |
34622231 |
Appl.
No.: |
11/840,404 |
Filed: |
August 17, 2007 |
Prior Publication Data
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Document
Identifier |
Publication Date |
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US 20070289942 A1 |
Dec 20, 2007 |
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Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
Issue Date |
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10990492 |
Nov 18, 2004 |
7287847 |
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Foreign Application Priority Data
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Nov 28, 2003 [JP] |
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2003-399219 |
Nov 2, 2004 [JP] |
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2004-319362 |
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Current U.S.
Class: |
347/63; 347/67;
347/65; 347/93 |
Current CPC
Class: |
B41J
2/1635 (20130101); B41J 2/1628 (20130101); B41J
2/1629 (20130101); B41J 2/1631 (20130101); B41J
2/1645 (20130101); B41J 2/1639 (20130101); B41J
2/1642 (20130101); B41J 2/1603 (20130101); B41J
2002/14403 (20130101); B41J 2002/14475 (20130101) |
Current International
Class: |
B41J
2/05 (20060101); B41J 2/175 (20060101) |
References Cited
[Referenced By]
U.S. Patent Documents
Foreign Patent Documents
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0 244 214 |
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Nov 1987 |
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FR |
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60-46264 |
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Mar 1985 |
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JP |
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6-023979 |
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Feb 1994 |
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JP |
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2000-94700 |
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Apr 2000 |
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JP |
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2002-326361 |
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Nov 2002 |
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JP |
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2002-355962 |
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Dec 2002 |
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JP |
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2003-19798 |
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Jan 2003 |
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JP |
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2003-145764 |
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May 2003 |
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JP |
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Other References
Derwent-acc-No. 1985-058497 Jujikawa J. cited by examiner.
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Primary Examiner: Deo; Duy-Vu N
Attorney, Agent or Firm: Fitzpatrick, Cella, Harper &
Scinto
Parent Case Text
This is a divisional application of application Ser. No.
10/990,492, filed Nov. 18, 2004, now U.S. Pat. No. 7,287,847 now
allowed.
Claims
What is claimed is:
1. An ink jet recording head comprising: a substrate provided at a
first surface with a plurality of energy generation elements for
generating energy for discharging ink, and an ink supply port,
penetrating between the first surface and a second surface which is
opposite the first surface, for supplying the ink to the energy
generation elements; a channel member for forming ink channels,
allowing the ink supply port to communicate with ink discharge
ports for discharging ink, the ink discharge ports corresponding to
the plurality of energy generation elements; and an organic film
layer formed from an organic film provided between the channel
member and the first surface of the substrate, wherein stacked
members comprising the organic film layer and another layer are
provided at a position facing an opening of the ink supply port on
a side of the first surface of the substrate and include a
plurality of holes penetrating the organic film layer and the other
layer so as to allow the supply port and the ink channels to
communicate with one another.
2. The ink jet recording head according to claim 1, wherein the
other layer is formed of an inorganic material.
3. The ink jet recording head according to claim 2, wherein the
inorganic material is a silicon nitride.
4. An ink jet recording head comprising: a substrate provided at a
first surface with a plurality of energy generation elements for
generating energy for discharging ink, and an ink supply port
penetrating between the first surface and a second surface, which
is opposite of the first surface, for supplying the ink to the
energy generation elements; a channel member for forming ink
channels, allowing the ink supply port to communicate with ink
discharge ports for discharging ink, the ink discharge ports
corresponding to the plurality of energy generation elements; and a
polyether amide resin layer formed from polyether amide resin and
provided between the channel member and the first surface of the
substrate, wherein polyether amide resin layer is provided at a
position facing an opening of the ink supply port at a side of the
first surface of the substrate and includes a plurality of holes
penetrating the polyether amide resin layer so as to allow the
supply port and the ink channels to communicate with one another.
Description
BACKGROUND OF THE INVENTION
1. Field of the Invention
The present invention relates to a method of manufacturing an ink
jet recording head for discharging liquid droplets to perform
recording, an ink jet recording head, and an ink jet cartridge,
concretely to a method of manufacturing an ink jet recording head
comprising a filter, an ink jet recording head, and an ink jet
cartridge.
2. Related Background Art
In recent years, to miniaturize an ink jet recording head, and
raising a density of heads, a method has been proposed in which an
electric control circuit for driving an ink discharge pressure
generation element is built in a substrate using a semiconductor
manufacturing technique. In order to supply ink to a plurality of
discharge ports, the ink jet recording head is structured such that
nozzles are passed through the substrate from the back surface of
the substrate, and connected to a common ink supply port, and the
ink is supplied to the respective nozzles from the common ink
supply port. With regard to the recording head, a method described
in U.S. Pat. No. 5,478,606 has been known as a method of
manufacturing the head with a remarkably high precision, in which a
distance between the ink discharge pressure generation element for
discharging the ink from the discharge ports, and the discharge
ports is reduced. When a silicon substrate is used as the substrate
of the ink jet recording head, as described in U.S. Pat. No.
6,139,761, it is possible to form the ink supply port using an
anisotropic etching technique.
As the reliability demanded for the ink jet recording head, dust
and foreign matters are inhibited from being introduced into the
nozzles. As a considered cause, the dust or foreign matters are
mixed into the nozzles in the process of manufacturing the ink jet
recording head, or the dust or foreign matters are sent together
with the ink and enter the nozzles. As a countermeasure against
this problem, it has been known that a filter is disposed on the
ink jet recording head.
For example, in U.S. Pat. No. 6,264,309, it has been described that
a resistance material layer for etching the ink supply port is
disposed on the surface provided with a heater, and a plurality of
holes are disposed in the resistance material layer to form the ink
supply ports and also the filter in the recording head constituted
of lamination of members for forming the discharge ports and
channels with respect to the silicon substrate provided with the
ink supply port. In U.S. Pat. No. 6,543,884, a constitution has
been described in which individual ink supply ports are disposed
for a plurality of ink jet chambers.
On the other hand, in Japanese Patent Application Laid-Open No.
2000-94700, it has been described that when the ink supply port is
formed in the silicon substrate, a membrane filter is disposed
simultaneously with the ink supply port using side etching with
respect to an etching-proof mask disposed on a side opposite to a
side on which a heater is disposed.
However, in the U.S. Pat. Nos. 6,264,309 and 6,543,884, there is a
fear that the dust or foreign matters are mixed into the nozzles
during lamination in the constitution in which the members for
forming the discharge ports and channels are laminated with respect
to the silicon substrate provided with the ink supply port. In the
method in which the holes are disposed in the thin film on the
silicon substrate constituting the filter before the ink supply
port is formed in the silicon substrate as described in these
documents, the ink supply port is formed in a state in which the
holes are made in a layer for stopping anisotropic etching,
described in the U.S. Pat. No. 6,139,761. Therefore, when the
method described in the above-described document is to be applied
to the method described in the U.S. Pat. No. 5,478,606, a soluble
resin for forming the channels is immersed in an etching solution
for forming the ink supply port, and there is a possibility that
precision of the manufactured head, or yield of high-precision head
manufacturing is adversely affected.
On the other hand, in the method of the Japanese Patent Application
Laid-Open No. 2000-94700, an insulating film formed of SiO.sub.2,
SiN or the like is used as the etching-proof mask, but the
insulating film (etching-proof mask) exposed on the back surface of
the silicon substrate is usually constituted as a deposited film
formed by sputtering or chemical vapor development. The film is
exposed in various solutions in subsequently performed steps and
corroded, or finely damaged during conveyance in a semiconductor
manufacturing apparatus during a manufacturing process in some
case. Therefore, it has been very difficult to keep the filter by
the insulating film without any defect until a final product is
manufactured.
SUMMARY OF THE INVENTION
The present invention has been developed in order to solve the
above-described technical problem, and an object thereof is to
provide a method of manufacturing an ink jet recording head, and
the recording head, and an ink jet cartridge manufactured by the
manufacturing method, in which a distance between an ink discharge
pressure generation element and a discharge port is set with a
remarkably high precision and in which discharge defects by foreign
matters such as dust and the like generated during the
manufacturing or using of the ink jet recording head are
suppressed.
To achieve the above-described object, according to the present
invention, there is provided a method of manufacturing an ink jet
head, comprising: a step of preparing a silicon substrate; a step
of forming a membrane having-a layer in which a plurality of holes
are disposed to constitute a filter mask, and a layer with which a
first surface is coated in such a manner that the first surface is
not exposed from the plurality of holes on the first surface of the
substrate; a step of forming a close contact enhancing layer on the
membrane formed on the substrate; a step of forming a channel
constituting member on the close contact enhancing layer to
constitute a plurality of discharge ports and a plurality of ink
channels communicating with the plurality of discharge ports; a
step of forming an ink supply port communicating with the plurality
of ink channels in the silicon substrate by anisotropic etching
from a second surface facing the first surface of the substrate;
and a step of forming a filter in a portion of the close contact
enhancing layer positioned in an opening of the ink supply port
using the layer of the membrane in which a plurality of holes are
disposed as the mask.
In the above-described method of manufacturing the ink jet head,
when the ink supply port is formed, the first surface is coated
with the layer in such a manner that the first surface is not
exposed from the plurality of holes disposed in the layer
constituting a filter pattern, and therefore the ink channel does
not communicate with the ink supply port. Therefore, even when the
channel is formed by a mold by a resin, the resin forming the mold
does not contact an etching solution of the anisotropic etching.
Furthermore, the filter by the close contact enhancing layer can be
formed on the surface of the substrate in which the ink channel is
disposed in a state the ink channel is formed, and therefore it is
not necessary to care about the mixing of the dust during the
manufacturing by lamination. Since the filter is not exposed to the
surface of the head chip even in a post step such as bonding to a
chip plate, there is not any possibility that the filter is damaged
by handling or the like. Therefore, there can be provided a method
of manufacturing the ink jet recording head, which solve the
above-described problem and which suppresses discharging defects by
foreign matters such as dust and the like generated during the
manufacturing or using of the ink jet recording head.
According to another aspect of the present invention, there is
provided a method of manufacturing an ink jet head, comprising: a
step of preparing a silicon substrate; a step of forming a first
inorganic film on a first surface of the substrate; a step of
forming a second inorganic film on the first inorganic film; a step
of forming a close contact enhancing layer on the second inorganic
film; a step of forming a channel constituting member on the close
contact enhancing layer to constitute a plurality of discharge
ports and a plurality of ink channels communicating with the
plurality of discharge ports; a step of forming an ink supply port
communicating with the plurality of ink channels in the silicon
substrate by anisotropic etching from a second surface facing the
first surface of the substrate; and a step of forming a plurality
of holes constituting a filter in a portion of the close contact
enhancing layer positioned in an opening of the ink supply port,
wherein the step of disposing the ink supply port comprises: a step
of blocking the communication of the ink channels with the ink
supply port by one of the close contact enhancing layer and the
second inorganic film, and allowing the ink channels to communicate
with the ink supply port after forming the ink supply port.
Even in the method of manufacturing the ink jet head, one of the
close contact enhancing layer and the second inorganic film blocks
the communication of the ink channels with the ink supply port
during the forming of the ink supply port. Therefore, even when the
channels are formed by a mold by a resin, the resin forming the
mold does not contact an etching solution of the anisotropic
etching. Furthermore, the filter by the close contact enhancing
layer is formed in the surface of the substrate in which the ink
channels are disposed in a state in which the ink channels are
formed, and the filter is not exposed to the surface of a head
chip. There can be provided a method of manufacturing the ink jet
recording head, in which, additionally, the above-described problem
is solved, and discharging defects by foreign matters such as dust
and the like generated during the manufacturing or using of the ink
jet recording head are suppressed.
Moreover, according to the present invention, there is provided an
ink jet recording head, comprising: a silicon substrate comprising
a plurality of energy generation elements for discharging ink, and
an ink supply port for supplying the ink to the energy generation
elements; a channel forming member for forming a plurality of
discharge ports for discharging the ink, corresponding to the
plurality of energy generation elements, and a plurality of ink
channels allowing the plurality of ink discharge ports to
communicate with the ink supply port; and a close contact enhancing
layer constituted of an organic film formed between the channel
forming member and the substrate, wherein a filter is formed by the
close contact enhancing layer in an opening of the ink supply port
on the side of the channel forming member.
The above-described ink jet recording head can be easily
manufactured by the above-described manufacturing method. As a
further preferable aspect, the channel forming member may be
constituted to form the organic film in a region of a part of the
opening of the liquid supply port. Accordingly, for example, when a
liquid flows into a liquid channel from the liquid supply port with
great force, a filter structure can be prevented from being pushed
and broken by the liquid. Therefore, strength against physical
breakage of the filter structure can be enhanced.
Moreover, the filter structure has a plurality of filter holes.
Assuming that a diameter of the discharge port or the liquid
channel whose diameter is smaller is A, and a diameter of the
filter hole is B, the filter may be constituted in such a manner
that a relation of A.gtoreq.B is established. When the diameter of
the discharge port or the liquid channel has this relation with
that of the filter hole, the foreign matters passed through the
filter structure can be discharged to the outside through the
discharge port, and therefore the discharge port and the liquid
channel are not prevented from being clogged with the foreign
matters.
Furthermore, according to the present invention, there is provided
an ink jet cartridge comprising this recording head.
BRIEF DESCRIPTION OF THE DRAWINGS
FIG. 1A is a schematic diagram showing an ink jet recording head
according to one embodiment of the present invention, and FIG. 1B
is a perspective view showing one example of an ink jet cartridge
to which the present invention is applicable;
FIGS. 2A, 2B, 2C, 2D, 2E, 2F, 2G, 2H, 2I, and 2J are schematic
sectional views showing steps of manufacturing the ink jet
recording head according to a first example of the present
invention in time series;
FIG. 3 is a sectional view showing an ink jet recording head
according to the first example of the present invention;
FIG. 4 is a schematic diagram showing a constitution of and around
a filter constituted on the back surface of the ink jet head shown
in FIG. 3;
FIGS. 5A, 5B, 5C, 5D, 5E, 5F, 5G, 5H, 5I, and 5J are schematic
sectional views showing steps of manufacturing the ink jet
recording head according to a second example of the present
invention in time series;
FIG. 6 is a sectional view showing the ink jet recording head
according to a third example of the present invention;
FIGS. 7A, 7B, 7C, 7D, 7E, 7F, 7G, and 7H are schematic sectional
views showing steps of manufacturing the ink jet recording head
according to a fourth example of the present invention in time
series;
FIGS. 8A, 8B, and 8C are explanatory views of the ink jet recording
head according to a fifth example of the present invention, FIG. 8A
is a top plan view, FIG. 8B is a 8B-8B sectional view of FIG. 8A,
and FIG. 8C is a 8C-8C sectional view of FIG. 8B; and
FIGS. 9A, 9B, and 9C are explanatory views of the ink jet recording
head according to a sixth example of the present invention, FIG. 9A
is a top plan view, FIG. 9B is a 9B-9B sectional view of FIG. 9A,
and FIG. 9C is a 9C-9C sectional view of FIG. 9B.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
Next, an embodiment of the present invention will be described with
reference to the drawings.
FIG. 1A is a schematic diagram showing an ink jet recording head
according to one embodiment of the present invention.
The ink jet recording head of the present embodiment has an Si
substrate 1 on which ink discharge pressure generation elements
(ink discharge energy generation elements) 2 are formed at a
predetermined pitch in parallel in two rows. In the Si substrate 1,
an ink supply port 13 formed by anisotropic etching of Si using an
etching-proof mask 5 (see FIG. 2A) is opened between two rows of
the ink discharge pressure generation elements 2. On the Si
substrate 1, ink discharge ports 11 opening above the respective
ink discharge pressure generation elements 2, and individual ink
channels communicating with the respective ink discharge ports 11
from the ink supply port 13 are formed.
This ink jet recording head is disposed in such a manner that the
surface in which the ink supply port 13 is formed faces a recording
surface of a recording medium. In this ink jet recording head,
pressure generated by the ink discharge pressure generation
elements 2 is applied to ink charged in the ink channels via the
ink supply port 13, accordingly the ink discharge ports 11 are
allowed to discharge ink liquid droplets, and the droplets are
attached to the recording medium to perform recording.
This ink jet recording head can be mounted on a printer, a copying
machine, a facsimile machine, an apparatus such as a word processor
having a printer section, and further an industrial recording
apparatus combined with various processing devices in a compound
manner. Moreover, when this ink jet recording head is used, the
recording can be performed with respect to various recording
mediums such as paper, thread, fiber, cloth, leather, metal,
plastic, glass, wood, and ceramic. It is to be noted that in the
present embodiment "recording" means that not only images having
meanings, such as characters and diagrams, but also images having
no meanings, such as patterns, are imparted to the recording
mediums.
Moreover, FIG. 1B is a perspective view showing one example of an
ink jet cartridge to which the ink jet recording head shown in FIG.
1A is mounted. An ink jet cartridge 300 comprises the
above-described ink jet recording head 100, and an ink storage
section 200 which stores ink to be supplied to the ink jet
recording head 100, and they are integrated.
First Example
Next, steps of manufacturing an ink jet recording head according to
a first example of the present invention will be described with
reference to FIGS. 2A to 2J. FIGS. 2A to 2J are schematic sectional
views showing the steps of manufacturing the ink jet recording head
according to the first example of the present invention. It is to
be noted that FIGS. 2A to 2J show sections in A-A line of FIG.
1B.
An Si substrate 1 shown in FIG. 2A has a crystal orientation of a
<100> plane. In the present example, the Si substrate 1
having the crystal orientation of the <100> plane will be
described as an example, but the plane orientation of the Si
substrate 1 is not limited to this orientation.
An SiO.sub.2 film 3 which was an insulating layer was formed on the
surface (first surface) of the Si substrate 1, a plurality of ink
discharge pressure generation elements 2 constituted of heat
generating resistors and the like were constituted on the film, and
further an electric signal circuit (not shown) was constituted.
Furthermore, an SiN film 4 for use as a protective film for the ink
discharge pressure generation elements 2 and the electric signal
circuit was formed over the surface. As to thicknesses of these
films 3, 4, the film thickness of the SiO.sub.2 film 3 was set to
1.1 .mu.m, and the film thickness of the SiN film 4 was set to 0.3
.mu.m in order to secure a balance between discharge and
accumulation of heat generated by the ink discharge pressure
generation elements 2 and exert a function of the recording head.
On the other hand, an etching-proof mask 5 and a polysilicon film 6
constituted of insulating films such as SiO.sub.2 and SiN films
were formed over the whole back surface (second surface) of the Si
substrate 1.
Next, a positive resist (not shown) was applied to the SiN film 4
on the surface of the Si substrate 1 by spin coating or the like,
and thereafter dried. As shown in FIG. 2B, the positive resist was
exposed and developed by ultraviolet rays, far ultraviolet rays
(deep-UV) and the like. Subsequently, a positive resist pattern was
used as a mask, the exposed SiN film 4 was dry-etched to form a
filter pattern 14, and the positive resist was peeled.
Next, as shown in FIG. 2C, the polysilicon film layer 6 on the back
surface of the Si substrate 1 was all removed by dry etching and
the like.
Next, as shown in FIG. 2D, polyether amide resin layers 7 were
formed on the SiN film 4 on the front surface of the Si substrate
1, and etching-proof mask (insulating film) 5 on the back surface,
and patterned in a predetermined manner. The polyether amide resin
layers 7 are formed of thermoplastic resins. Since the polyether
amide resin layers 7 fulfill a function of enhancing adhesion of a
coating resin layer 9 constituting a nozzle forming member as
described later, the polyether amide resin layers 7 will be
referred to also as "adhesion enhancing layers". In the present
example, thermoplastic polyether amide (trade name: HL-1200
manufactured by Hitachi Chemical Co., Ltd.) was used as a material
of the close contact enhancing layer 7. This product has been on
the market in a state of a solution obtained by dissolving
thermoplastic polyether amide in a solvent. When thermoplastic
polyether amide commercially available in this manner is applied
onto the opposite surfaces of the Si substrate 1 by spin coating or
the like, a positive resist (not shown) is further formed and
patterned, and accordingly the close contact enhancing layer 7 can
be formed as shown in FIG. 2D. In the present example, the film
thickness of the close contact enhancing layer 7 was set to 2
.mu.m.
Next, as shown in FIG. 2E, a pattern layer 8 constituting an ink
channel portion was formed of a soluble resin on the surface of the
Si substrate 1 on which the ink discharge pressure generation
elements 2 were constituted. As the soluble resin, for example, a
deep-UV resist (trade name: ODUR manufactured by Tokyo Ohka Kogyo
Co., Ltd.) is usable. This is applied onto the surface of the Si
substrate 1 by the spin coating or the like, and thereafter exposed
and developed by the deep-UV light to form the pattern layer 8.
Next, as shown in FIG. 2F, the coating resin layer 9 formed of a
photosensitive resin was formed on the pattern layer 8 by the spin
coating or the like. Furthermore, a photosensitive water-repellent
layer 10 formed of a dry film was disposed on the coating resin
layer 9. Moreover, the coating resin layer 9 and the
water-repellent layer 10 were exposed and developed by the
ultraviolet rays, deep-UV light or the like to form an ink
discharge port 11.
Next, as shown in FIG. 2G, the surface and side surfaces of the Si
substrate 1 on which the pattern layer 8, the coating resin layer 9
and the like were patterned/formed were coated by a protective
material 12 applied by the spin coating or the like. The protective
material 12 is formed of a material which is capable of
sufficiently resisting a strong alkali solution for use in
anisotropically etching the Si substrate 1 in a subsequent step,
and therefore the water-repellent layer 10 and the like can be
prevented from being deteriorated during the anisotropic etching.
The insulating film 5 on the back surface of the Si substrate 1 was
wet-etched or treated otherwise using the polyether amide resin
layer 7 as a mask, and accordingly patterned. Then, a starting
surface for the anisotropic etching was exposed on the back surface
of the Si substrate 1.
Next, as shown in FIG. 2H, an ink supply port 13 was formed in the
Si substrate 1. The ink supply port 13 was formed, for example, by
the anisotropic etching of the Si substrate 1 using strong alkali
solutions such as tetramethyl ammonium hydroxide (TMAH) and
potassium hydroxide (KOH). Thereafter, the polyether amide resin
layer 7 on the back surface of the Si substrate 1 was removed by
the dry etching or the like, and a portion positioned on the ink
supply port 13 of the SiO.sub.2 film 3 was removed by the wet
etching. It is to be noted that burrs of the insulating film 5
generated on the periphery of an opening edge of the ink supply
port 13 are removed during the wet etching of the SiO.sub.2 film 3,
the burrs generated on the insulating film 5 are prevented from
being dropped as foreign matters.
Next, as shown in FIG. 2I, the close contact enhancing layer 7 was
patterned from the back surface of the Si substrate 1 by the dry
etching using the SiN film 4 as a mask. As a result, the close
contact enhancing layer 7 was pattern in the same manner as in the
filter pattern 14 formed on the SiN film 4 to constitute a filter
16 constituted of the SiN film 4 which was an inorganic film and
the close contact enhancing layer 7 which was an organic film. It
is to be noted that the SiN film 4 used as a mask material, if
unnecessary, may be removed after the patterning of the close
contact enhancing layer 7. In this case, the filter 16 is
constituted only of the close contact enhancing layer 7 which is an
organic film.
Next, as shown in FIG. 2J, the protective material 12 was removed.
Furthermore, the material (thermoplastic resin) of the pattern
layer 8 was eluted and removed through the ink discharge port 11
and the ink supply port 13, and accordingly an ink channel and a
foam chamber were formed between the Si substrate 1 and the coating
resin layer 9. As to the thermoplastic resin which is the material
of the pattern layer 8, this thermoplastic resin is developed and
softened by exposure of the whole surface of a wafer with the
deep-UV light, and the wafer is ultrasonically immersed during the
developing, if necessary, so that the resin can be eluted through
the ink discharge port 11 and the ink supply port 13. Thereafter,
the wafer is rotated at a high speed, a liquid for the ultrasonic
immersion is blown off, and the insides of the ink channel and the
foam chamber are dried.
The wafer in which a nozzle portion was formed by the
above-described steps was separated/cut into chips with a dicing
saw or the like, an electric wiring (not shown) or the like for
driving the ink discharge pressure generation elements 2 was bonded
to each chip, thereafter a chip tank member (not shown) storing ink
to be supplied to the ink supply port 13 was connected to the ink
supply port 13 of each chip, and an ink jet recording head was
completed (see FIG. 3).
Filter holes 16a of the filter 16 has not only a function of the
filter but also a function of a passage of the ink supplied to
nozzles through the ink supply port 13 from a chip tank (not
shown). To enhance a performance of the filter, a diameter of each
filter hole 16a is set to be as small as possible, and the filter
holes 16a are preferably arranged while setting an interval between
the filter holes 16a to be as small as possible. On the other hand,
however, when the filter holes 16a are formed in this manner,
pressure loss (flow resistance) is caused, the ink does not flow
smoothly, and an ink discharge speed is adversely affected.
Therefore, it is not preferable to excessively reduce the diameters
and the intervals of the filter holes 16a. Thus, a tradeoff
relation is established between the performance and the flow
resistance of the filter comprising the filter holes 16a.
FIG. 4 is a schematic diagram showing a constitution of and around
the filter constituted on the back surface of the ink jet head
shown in FIG. 3.
In the present example, the diameter of each filter hole 16a of the
filter 16 was set to 6 .mu.m, the interval between the adjacent
filter holes 16a was set to 3 .mu.m, and the filter holes were
arranged at equal intervals. In the present example, the diameters
and the intervals of the filter holes 16A were set in this manner.
These dimensions are preferably set to be suitable for individual
ink jet recording heads, that is, in such a manner as to establish
the above-described tradeoff relation.
To prevent the ink discharge port 11 and the like from being
clogged with foreign matters passed through the filter 16, in the
constitution of the present example, assuming that a diameter of
the discharge port 11 or the ink channel of the nozzle forming
member 9 whose diameter is smaller (the diameter of the ink
discharge port 11 in the constitution shown in FIG. 3) is A, and a
diameter of the filter hole 16a is B, the filter has a relation of
A.gtoreq.B. When the diameter of the ink discharge port 11 or the
ink channel and that of the filter hole 16a has this relation, the
foreign matters passed through the filter 16 are passed through the
ink channel and the ink discharge port 11 and discharged to the
outside, and therefore the ink channel and the ink discharge port
11 are not clogged with the foreign matters.
Second Example
Next, steps of manufacturing an ink jet recording head according to
a second example of the present invention will be described with
reference to FIGS. 5A to 5J. FIGS. 5A to 5J are schematic sectional
views showing the steps of manufacturing the ink jet recording head
according to the second example of the present invention, and FIGS.
5A to 5J show sections in A-A line of FIG. 1B.
An Si substrate 21 shown in FIG. 5A has a crystal orientation of a
<100> plane. Even in the present example, the Si substrate 21
having the crystal orientation of the <100> plane will be
described as an example, but the plane orientation of the Si
substrate 21 is not limited to this orientation.
An etching-proof mask 25 and a polysilicon film 26 constituted of
insulating films such as SiO.sub.2 and SiN films were formed over
the whole back surface (second surface) of the Si substrate 21, and
an SiO.sub.2 film 23 was formed into a film thickness of 1.1 .mu.m
as an insulating layer on the surface (first surface) of the Si
substrate 21.
As to the SiO.sub.2 film 23, a positive resist (not shown) was
applied by spin coating or the like, dried, and thereafter exposed
and developed by ultraviolet rays, deep-UV light and the like.
Subsequently, a positive resist pattern was used as a mask, the
exposed SiN film 23 was removed by dry etching or the like, and the
positive resist was peeled. The film can accordingly be patterned.
In the present example, a pattern constituting a membrane filter
structure 36 described later was formed on the SiO.sub.2 film 23. A
diameter and an interval of a filter hole was set to 6 .mu.m and 3
.mu.m, respectively, in the same manner as in the first
example.
Next, as shown in FIG. 5B, a plurality of ink discharge pressure
generation elements 22 constituted of heat generating resistors,
and an electric signal circuit (not shown) were constituted on the
SiO.sub.2 film 23, and further, and an SiN film 24 for use as a
protective film for the ink discharge pressure generation elements
22 and the electric signal circuit was formed over the whole
surface. Thereafter, the polysilicon film 26 on the back surface of
the Si substrate 21 was all removed by the dry etching or the
like.
Next, as shown in FIG. 5C, polyether amide resin layers 27 were
formed on the SiN film 24 on the front surface of the Si substrate
21 and the etching-proof mask (insulating film) 25 on the back
surface, and patterned in a predetermined manner. In the present
example, a film thickness of the close contact enhancing layer 27
was set to 2 .mu.m.
Next, as shown in FIG. 5D, a pattern layer 28 constituting an ink
channel portion was formed of a soluble resin on the surface of the
Si substrate 21 on which the ink discharge pressure generation
elements 22 were constituted. As the soluble resin, for example, a
deep-UV resist is usable. This is applied onto the surface of the
Si substrate 21 by the spin coating or the like, and thereafter
exposed and developed by the deep-UV light to form the pattern
layer 28.
Next, as shown in FIG. 5E, a coating resin layer 29 formed of a
photosensitive resin was formed on the pattern layer 28 by the spin
coating or the like. Furthermore, a photosensitive water-repellent
layer 30 formed of a dry film was disposed on the coating resin
layer 29. Moreover, the coating resin layer 29 and the
water-repellent layer 30 were exposed and developed by the
ultraviolet rays, deep-UV light or the like to form an ink
discharge port 31.
Next, as shown in FIG. 5F, the surface and side surfaces of the Si
substrate 21 on which the pattern layer 28, the coating resin layer
29 and the like were patterned/formed were coated by a protective
material 32 applied by the spin coating or the like. The protective
material 32 is formed of a material which is capable of
sufficiently resisting a strong alkali solution for use in
anisotropic etching in a subsequent step, and therefore the
water-repellent layer 30 and the like can be prevented from being
deteriorated during the anisotropic etching. The insulating film 25
on the back surface of the Si substrate 21 was wet-etched or
treated otherwise using the polyether amide resin layer 27 as a
mask, and accordingly patterned. Then, a starting surface for the
anisotropic etching was exposed on the back surface of the Si
substrate 21.
Next, as shown in FIG. 5G, an ink supply port 33 was formed in the
Si substrate 21. The ink supply port 33 was formed, for example, by
the anisotropic etching of the Si substrate 21 using strong alkali
solutions such as tetramethyl ammonium hydroxide (TMAH) and
potassium hydroxide (KOH).
Next, as shown in FIG. 5H, the SiO.sub.2 film 23 was used as a
mask, and the SiN film 24 was patterned from the back surface of
the Si substrate 21 by the dry etching. As a result, the SiN film
24 was patterned in the same manner as in a filter pattern 35 (see
FIG. 5A).
Next, as shown in FIG. 5I, the close contact enhancing layer 27 was
patterned from the back surface of the Si substrate 21 by the dry
etching using the SiO.sub.2 film 23 and SiN film 24 patterned as
described above as masks. At this time, an SiO.sub.2 film 23' (see
FIG. 5H) attached to the surface of a portion of the SiN film 24
patterned into a filter pattern on the side of the ink supply port
33 was removed in the patterning step of the close contact
enhancing layer 27. As a result, adhesion enhancing layer 27 was
patterned in the same manner as in the filter pattern 35 to
constitute the membrane filter structure 36 constituted of the SiN
film 24 and the close contact enhancing layer 27. It is to be noted
that the SiN film 24 used as a mask material, if unnecessary, may
be removed after the patterning of the close contact enhancing
layer 27. In this case, the membrane filter structure 36 is
constituted only of the close contact enhancing layer 27 which is
an organic film.
It is to be noted that burrs of the insulating film 25 generated on
the periphery of an opening edge of the ink supply port 33 are
removed together with the SiO.sub.2 film 23' in the step of
patterning the close contact enhancing layer 27, and therefore,
unlike a conventional technique, the burrs generated on the
insulating film 25 are prevented from being dropped as foreign
matters.
Next, as shown in FIG. 5J, the protective material 32 was removed.
Furthermore, the material (thermoplastic resin) of the pattern
layer 28 was eluted through the ink discharge port 31 and the ink
supply port 33, and accordingly an ink channel and a foam chamber
were formed between the Si substrate 21 and the coating resin layer
29.
The Si substrate 21 in which a nozzle portion was formed by the
above-described steps was separated/cut into chips with a dicing
saw or the like, an electric wiring (not shown) or the like for
driving the ink discharge pressure generation elements 22 was
bonded to each chip, thereafter a chip tank member (not shown)
storing ink to be supplied to the ink supply port 33 was connected
to the ink supply port 33 of each chip, and an ink jet recording
head was completed.
Even in the constitution of the present example, to prevent the ink
discharge port 31 and the like from being clogged with foreign
matters passed through the membrane filter structure 36, as shown
in FIG. 5J, assuming that a diameter of the discharge port 31 or
the ink channel of the nozzle forming member 29 whose diameter is
smaller (the diameter of the ink discharge port 31 in the
constitution shown in FIG. 5J) is A, and a diameter of the filter
hole 36a is B, the structure has a relation of A.gtoreq.B. When the
diameter of the ink discharge port 31 or the ink channel and that
of the filter hole 36a has this relation, the foreign matters
passed through the membrane filter structure 36 are passed through
the ink channel and the ink discharge port 31 and discharged to the
outside, and therefore the ink channel and the ink discharge port
31 are not clogged with the foreign matters.
Third Example
FIG. 6 is a sectional view showing an ink jet recording head
according to a third example of the present invention.
In the ink jet recording head of the present example, in a coating
resin layer (nozzle forming member) 49 and a close contact
enhancing layer 47 disposed on a first surface (upper surface) of
an Si substrate 41, a portion existing in a middle area of an ink
supply port 53 constitutes a support portion 60 which supports a
membrane filter structure 56. The support portion 60 can be easily
constituted by appropriately changing a shape of the pattern layer
in the steps of manufacturing the ink jet recording head described
in the first and second examples. Accordingly, for example, when
ink flows into a nozzle channel from the ink supply port 53 with
great force, the membrane filter structure 56 can be prevented from
being pushed and broken by the ink. Therefore, strength of the
membrane filter structure 56 against physical breakage can be
enhanced.
It is to be noted that other constitutions of the ink jet recording
head shown in FIG. 6 is similar to that shown in FIG. 3 and the
like, and therefore detailed description thereof is omitted.
Moreover, even in the constitution of the present example, to
prevent the ink discharge port 51 and the like from being clogged
with foreign matters passed through the membrane filter structure
56, as shown in FIG. 6, assuming that a diameter of the discharge
port 51 or the ink channel of the nozzle forming member 49 whose
diameter is smaller (the diameter of the ink discharge port 51 in
the constitution shown in FIG. 6) is A, and a diameter of the
filter hole 56a is B, the structure has a relation of A.gtoreq.B.
When the diameter of the ink discharge port 51 or the ink channel
and that of the filter hole 56a has this relation, the foreign
matters passed through the membrane filter structure 56 are passed
through the ink channel and the ink discharge port 51 and
discharged to the outside, and therefore the ink channel and the
ink discharge port 51 are not clogged with the foreign matters.
Fourth Example
Next, steps of manufacturing an ink jet recording head according to
a fourth example of the present invention will be described with
reference to FIGS. 7A to 7H. FIGS. 7A to 7H are schematic sectional
views showing the steps of manufacturing the ink jet recording head
according to the fourth example of the present invention, and FIGS.
7A to 7H show sections in A-A line of FIG. 1B.
The steps of manufacturing the ink jet recording head described
above in the first and second examples are suitable for a case
where a resin for use as a close contact enhancing layer does not
have any photosensitive property. On the other hand, manufacturing
steps of the present example are suitable for a case where the
close contact enhancing layer is formed of a resin having the
photosensitive property. The manufacturing method of the present
example will be described hereinafter in comparison with the first
example.
First, as shown in FIG. 7A, an Si substrate 61 having a crystal
orientation of a <100> plane was prepared, and an SiO.sub.2
film 63 which was an insulating layer was formed on the surface
(first surface) of this substrate. On the film, an ink discharge
pressure generation element 62 and an electric signal circuit (not
shown) were constituted, and an SiN film 64 constituting a
protective film for the element and circuit was formed over the
whole surface. On the other hand, on the back surface (second
surface) of the substrate, an etching-proof mask 65 and a
polysilicon film 66 were formed over the whole surface. It is to be
noted that a sacrificial layer 75 selectively etchable with respect
to a substrate material is formed on the first surface of the Si
substrate 61.
Next, as shown in FIG. 7B, after removing the polysilicon film 66
on the back surface of the substrate, resin layers 67 were formed
on the front and back surfaces of the substrate. In the present
example, the same material was used on the front and back surfaces
of the substrate, but different materials may be used. Here, when a
photosensitive resin material such as a photosensitive polyimide
resin is used as the material of the resin layer 67 on the front
surface of the substrate, as shown in FIG. 7C, a filter portion 67a
can be easily formed by photolithography. The resin layer disposed
on the back surface of the substrate also forms a pattern
constituting a supply port opening in a known method.
Next, as shown in FIG. 7D, a pattern layer 68 constituting an ink
channel was formed. Moreover, as shown in FIG. 7E, a coating resin
layer 69 formed of a photosensitive resin was formed on the layer,
and a water-repellent layer 70 was disposed. Thereafter, an ink
discharge port 71 was formed by patterning, and, as shown in FIG.
7F, members stacked on the first surface of the Si substrate were
coated with a protective material 72. The etching-proof mask 65 was
patterned using the resin layer 67 as a mask.
Thereafter, as shown in FIG. 7G, an ink supply port was formed by
anisotropic etching using a strong alkali solution from the back
surface of the Si substrate. Here, if the etching reaches the
sacrificial layer, isotropic etching is started, but the SiO.sub.2
film 63 and the SiN film are formed on the substrate front surface,
and the pattern layer does not contact the alkali solution.
Thereafter, the SiO.sub.2 film 63 was removed by wet etching, the
SiN film 64 was removed by dry etching, and then the filter 67a was
exposed. Thereafter, the protective material 72 was removed, and
the pattern layer 68 was removed to form an ink channel and a foam
chamber. Therefore, steps similar to those of the first example
were performed to complete the ink jet recording head.
Fifth Example
FIGS. 8A to 8C are sectional views showing an ink jet recording
head according to a fifth example of the present invention. FIGS.
8A to 8C are explanatory views of the ink jet recording head
according to the fifth example of the present invention, FIG. 8A is
a top plan view, FIG. 8B is a 8B-8B sectional view of FIG. 8A, and
FIG. 8C is a 8C-8C sectional view of FIG. 8B.
In the recording head of the present example, as shown in FIG. 8A,
a first discharge port row constituted of first discharge ports 81a
each having a predetermined discharge port diameter, and a second
discharge port row constituted of second discharge ports 81b each
having a discharge port diameter smaller than that of the first
discharge port 81a are disposed in such a manner as to hold an ink
supply port 82 therebetween. A liquid discharged from the first
discharge port is more than that discharged from the second
discharge port. In the present example, as apparent from FIGS. 8B
and 8C, a close contact enhancing layer 85 forming a filter 85a was
disposed over the first surface of an Si substrate 84 on which an
SiO.sub.2 film 84a and an SiN film excluding the vicinity of an ink
discharge pressure generation element 83 of an ink channel. As in
the third example, a support portion 86a for supporting the filter
was disposed in a part of a coating resin layer (nozzle forming
member) 86. Here, reference numeral 87 denotes a water-repellent
layer, and 88 denotes an etching-proof mask layer.
In the present example, the filter 85a is partitioned on first and
second discharge port row sides by the support portion 86a. Here, a
filter for the first discharge port row has a filter aperture
diameter equal to that of a filter for the second discharge port
row, but the support member is disposed on the second discharge
port row from a middle portion of the ink supply port, and
therefore an area of the filter for the first discharge port row is
larger than that of the filter for the second discharge port
row.
In this case, ink can be supplied to the ink channel comprising the
first discharge ports having a large liquid discharge amount
without any ink supply shortage.
Sixth Example
FIGS. 9A to 9C are sectional views showing an ink jet recording
head according to a sixth example of the present invention. FIGS.
9A to 9C are explanatory views of the ink jet recording head
according to the sixth example of the present invention, FIG. 9A is
a top plan view, FIG. 9B is a 9B-9B sectional view of FIG. 9A, and
FIG. 9C is a 9C-9C sectional view of FIG. 9B.
In the recording head of the present example, as shown in FIG. 9A,
a first discharge port row constituted of first discharge ports 91a
each having a predetermined discharge port diameter, and a second
discharge port row constituted of second discharge ports 91b each
having a discharge port diameter smaller than that of the first
discharge port 91a are disposed in such a manner as to hold an ink
supply port 92 therebetween. A liquid discharged from the first
discharge port is more than that discharged from the second
discharge port. In the present example, as apparent from FIGS. 9B
and 9C, a close contact enhancing layer 95 forming a filter was
disposed over the first surface of an Si substrate 94 on which an
SiO.sub.2 film 94a and an SiN film excluding the vicinity of an ink
discharge pressure generation element 93 of an ink channel. As in
the third example, a support portion 96a for supporting the filter
was disposed in a part of a coating resin layer (nozzle forming
member) 96. Here, reference numeral 97 denotes a water-repellent
layer, and 98 denotes an etching-proof mask layer.
In the present example, the filter is partitioned into a filter 95a
on the first discharge port row side, and a filter 95b on the
second discharge port row side by the support portion 96a. Here,
the filter 95a for the first discharge port row has a filter
aperture diameter larger than that of the filter for the second
discharge port row, and the filter for the first discharge port row
also has a larger area.
In this case, ink can be supplied to the ink channel comprising the
first discharge ports having a large liquid discharge amount
without any ink supply shortage in the same manner as in the fifth
example.
Moreover, in the present example, a protective member 96b is
disposed in order to enhance a strength of the support portion 96a.
In the present example, the protective member has a shape of the
support portion continued to an ink channel wall, but is not
limited to this shape.
This application claims priority from Japanese Patent Application
Nos. 2003-399219 filed Nov. 28, 2003 and 2004-319362 filed Nov. 2,
2004, which are hereby incorporated by reference herein.
* * * * *